I have an old galvanized plumbing system with a tub attached to a drum shaped trap of some kind with a plug that unscrews mounted in the woood floor adjacent to the tub. I assume this is a p trap of some kind. It was probably installed in 1937. Should I keep this or figure out how to remove it and replace with conventional ABS p trap and new drain and overflow? The existing drain and overflow leaks, is corroded, and drain is slow.